After the Avengers there seems to be dozens of people trying to become Heroes and villains and NYC is caught in the crossfire. With the Avengers "gone" it seems like NYC needs protecting enter : Heroes For Hire.

All of their origins can be ties to MCU

Jessica Jones got her powers by car with her family when they collided with a military convoy carrying radioactive chemicals. Her family was killed and, after spending several months in a coma, she was placed in foster care and adopted by the Jones family. (That convoy could have been in Harlem and happened during Hulk vs Abomination in Harlem.)

Misty Knight could have lost her arm during the Chitauri attack and got his new arm from Tony Stark.

Luke Cage could have gotten his powers from Roxxon.

Clay Quartermain would be their SHIELD rep, who reports to Nick Fury what's going on.

Cameos I could see in this show

Shang-Chi
Tarantula
References to the Punisher
References to The Hood
Wrecking Crew